Update llm-gpt4all examples for latest release

!stable-docs

Refs https://github.com/simonw/llm-gpt4all/issues/16

docs/index.md

@@ -50,7 +50,7 @@ Or you can {ref}`install a plugin <installing-plugins>` and use models that can
 llm install llm-gpt4all
 
 # Download and run a prompt against the Orca Mini 7B model
-llm -m orca-mini-7b 'What is the capital of France?'
+llm -m orca-mini-3b-gguf2-q4_0 'What is the capital of France?'
 ```
 To start {ref}`an interactive chat <usage-chat>` with a model, use `llm chat`:
 ```bash

docs/other-models.md

@@ -16,7 +16,7 @@ Run `llm models` to see the expanded list of available models.
 
 To run a prompt through one of the models from GPT4All specify it using `-m/--model`:
 ```bash
-llm -m orca-mini-7b 'What is the capital of France?'
+llm -m orca-mini-3b-gguf2-q4_0 'What is the capital of France?'
 ```
 The model will be downloaded and cached the first time you use it.
 

docs/plugins/installing-plugins.md

@@ -25,7 +25,7 @@ llm models --options
 ```
 To run a prompt against a newly installed model, pass its name as the `-m/--model` option:
 ```bash
-llm -m orca-mini-7b 'What is the capital of France?'
+llm -m orca-mini-3b-gguf2-q4_0 'What is the capital of France?'
 ```
 
 ## Listing installed plugins